Variable-Capacity Compressor

ABSTRACT

To prevent operation failure caused by adhesion of a lubricating oil of a control valve for controlling a discharge displacement. A partition member  150  is provided to partition a suction chamber  141  into: a first space  141   a,  to which a suction passage is connected, and in which a lubricating oil is separated from a refrigerant gas and is stored; and a second space  141   b,  to which a suction hole  103   a  is connected, and to which the refrigerant gas from which the lubricating oil that has been separated is introduced via a communication hole  150   a,  and it is configured so that a pressure in the second space  141   b  can be introduced to a control valve  300  via a pressure introducing passage  147.

TECHNICAL FIELD

The present invention relates to a variable-displacement compressor, andmore specifically, relates to a variable-displacement compressor thatvaries a discharge displacement of a refrigerant gas by controlling apressure in a crank chamber by a control valve depending on a pressurein a suction chamber.

BACKGROUND ART

For example, Patent Document 1 discloses this type of avariable-displacement compressor. In the variable-displacementcompressor, a control valve is provided in a communication passagecommunicating between a discharge chamber and a crank chamber on a backside of a piston. The control valve controls a pressure in the crankchamber by controlling an opening of the communication passage dependingon a pressure in a suction chamber, and a stroke of the piston ischanged. Accordingly, a discharge displacement of a refrigerant gas isvaried. Specifically, the suction chamber is connected to the controlvalve by a pressure introducing passage, and a pressure in the suctionchamber is introduced to the control valve. The control valve controlsan opening of the communication passage by detecting a change in apressure in the suction chamber, an amount of a high pressurerefrigerant gas to be introduced to the crank chamber is increased ordecreased, and a stroke of the piston is changed by changing aninclination (angle of inclination) of a swash plate. Accordingly, adischarge displacement of a refrigerant gas is increased or decreased.

REFERENCE DOCUMENT LIST Patent Document

Patent Document 1: Japanese Patent Application Laid-open Publication No.2012-127233

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

In such a variable-displacement compressor, a lubricating oil is mixedin a refrigerant gas to lubricate each component of the compressor.Therefore, in a configuration like a conventional variable-displacementcompressor, in which a refrigerant gas including a lubricating oil to bereturned from a suction passage to a suction chamber via an externalrefrigerant circuit after being discharged from the compressor isdirectly introduced to a control valve from a pressure introducingpassage, sensitivity of the control valve might be lowered since thelubricating oil flows into the control valve especially in a case inwhich a large amount of the oil is circulating.

The present invention is focused on the above issue and seeks to providea variable-displacement compressor that can control an amount of alubricating oil flowing into a control valve and prevent sensitivityreduction of the control valve caused by inflow of the lubricating oil.

Means for Solving the Problems

Therefore, a variable-displacement compressor according to the presentinvention includes: a piston that compresses a refrigerant gas drawnfrom a suction chamber via a suction hole and discharges the refrigerantgas to a discharge chamber via a discharge hole; a first passage thatcommunicates between a crank chamber on a back side of the piston andthe discharge chamber; a control valve provided in the first passage andthat controls an opening of the first passage; a second passage thatcommunicates between the crank chamber and the suction chamber, and thatis provided with an orifice; and a pressure introducing passageconfigured to introduce a pressure in the suction chamber to the controlvalve. The control valve controls an opening of the first passagedepending on the pressure in the suction chamber, which has beenintroduced from the pressure introducing passage, so as to control apressure in the crank chamber, so that a stroke of the piston ischanged, and accordingly, a discharge displacement of a refrigerant gasis varied. The suction chamber includes a storage area for separating alubricating oil from a refrigerant gas inflowing from a suction passageand for storing the lubricating oil, and the pressure introducingpassage is open to an inflow area into which the refrigerant gas, fromwhich the lubricating oil has been separated, flows, so as to introducethe pressure in the suction chamber to the control valve.

Effect of the Invention

According to the variable-displacement compressor according to thepresent invention, the suction chamber includes the storage area forstoring the lubricating oil separated from the refrigerant gas inflowedfrom the suction passage, and the pressure introducing passage is opento an inflow area into which the refrigerant gas, from which thelubricating oil has been separated, flows. Therefore, an amount of thelubricating oil in the refrigerant gas flowing into the control valvevia the pressure introducing passage can be reduced, and sensitivityreduction of the control valve caused by inflow of the lubricating oilcan be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating an embodiment of avariable-displacement compressor according to the present invention.

FIG. 2 is a cross-sectional view of a control valve applied to theembodiment.

FIG. 3 is a view illustrating a valve plate viewed from a cylinder blockside, according to the embodiment.

FIG. 4 is a view illustrating a discharge valve forming body viewed froma cylinder block side, according to the embodiment.

FIG. 5 is a view illustrating a cylinder head viewed from a cylinderblock side, according to the embodiment.

FIG. 6 is a view illustrating a head gasket viewed from a cylinder blockside, according to the embodiment.

FIG. 7 is a cross-sectional view taken along with a line A-O-A viewedfrom arrows A, in a state in which the head gasket illustrated in FIG. 6is assembled.

FIG. 8 is a cross-sectional view taken along with a line viewed fromarrows B, illustrated in FIG. 6.

FIG. 9 is a cross-sectional view taken along with a line viewed fromarrows C, in a state in which the cylinder head illustrated in FIG. 5 isassembled.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be describedwith reference to the accompanying drawings.

FIG. 1 illustrates a schematic configuration of a variable-displacementcompressor according to a first embodiment of the present invention, andFIG. 1 is an example of a clutch-less variable-displacement compressorfor use in a vehicle air conditioning system.

In FIG. 1, a variable-displacement compressor 100 includes: a cylinderblock 101 in which multiple cylinder bores 101 a are formed; a fronthousing 102 provided at one end of the cylinder block 101; and acylinder head 104 provided at another end of the cylinder block 101 viaa valve plate 103.

A drive shaft 110 is provided so as to cross in a crank chamber 140formed by the cylinder block 101 and the front housing 102. A swashplate 111 is arranged around an intermediate portion in an axialdirection of the drive shaft 110. The swash plate 111 is connected to arotor 112, which is fixed to the drive shaft 110, via a linkage 120, andis supported so that an inclination thereof can be varied by the driveshaft 110.

The linkage 120 includes: a first arm 112 a arranged so as to protrudefrom the rotor 112; a second arm 111 a arranged so as to protrude fromthe swash plate 111; and a link arm 121 rotatably connected at one endto the first arm 112 a via a first connection pin 122, and rotatablyconnected at the other end to the second arm 111 a via the secondconnection pin 123.

A through hole 111 b of the swash plate 111 is formed so as to beinclined within a range of the maximum inclination (θ max) to theminimum inclination (θ min). A minimum-inclination restricting portioncoming into contact with the drive shaft 110 is formed to the throughhole 111 b. In a case in which an inclination of the swash plate 111orthogonal to the drive shaft 110 is set as 0°, the minimum inclinationrestricting portion of the through hole 111 b allows the swash plate 111to be inclined to approximately 0°. The maximum inclination of the swashplate 111 is restricted when the swash plate 111 comes into contact withthe rotor 112.

A disinclining spring 114 for biasing the swash plate 111 toward theminimum inclination is mounted around the drive shaft 110 between therotor 112 and the swash plate 111. Also, an inclining spring 115 forbiasing the swash plate 11 in a direction increasing an inclination ofthe swash plate 111 is mounted around the drive shaft 110 between theswash plate 111 and a spring support member 116 provided to the driveshaft 110. Herein, a biasing force of the inclining spring 115 at theminimum inclination is set to be greater than that of the disincliningspring 114. When the drive shaft 110 is not rotating, the swash plate111 is arranged at an inclination angle at which the biasing force ofthe disinclining spring 114 and the biasing force of the incliningspring 115 are balanced.

One end of the drive shaft 110 is extended to an outer side of the fronthousing 102, passing through a boss portion 102 a of the front housing102, and connected to a power transmission device (not illustrated). Ashaft seal device 130 is inserted between the drive shaft 110 and theboss portion 102 a to block the inside of the crank chamber 140 from theoutside.

The connected body of the drive shaft 110 and the rotor 112 is supportedby bearings 131 and 132 in a radial direction and supported by a bearing133 and a thrust plate 134 in a thrust direction. A gap between thethrust plate 134 of the drive shaft 110 and a portion coming intocontact with the thrust plate 134 is adjusted to a predetermined gap byan adjusting screw 135. Power from an external driving source (vehicleengine) is transmitted to a power transmission device, and the driveshaft 110 rotates in synchronization with the power transmission device.

A piston 136 is arranged in the cylinder bore 101 a. An outer peripheryof the swash plate 111 is accommodated in an internal space of an endportion of the piston 136 protruding toward the crank chamber 140. Theswash plate 111 is synchronized with the piston 136 via a pair of shoes137. Therefore, the piston 136 reciprocates in the cylinder bore 101 aby rotation of the swash plate 111.

In the cylinder head 104, a suction chamber 141 defined by an annularpartition wall 104 b is formed at a center thereof, and a dischargechamber 142 defined by the partition wall 104 b and an external wall isformed so that the discharge chamber 142 circularly surrounds thesuction chamber 141. The suction chamber 141 is communicated with thecylinder bore 101 a via a suction hole 103 a formed in the valve plate103 and a suction valve (not illustrated) formed in a suction valveforming body. The discharge chamber 142 is communicated with thecylinder bore 101 a via a discharge hole 103 b formed in the valve plate103 and a discharge valve 138 a formed in a discharge valve forming body138, illustrated in FIG. 4.

A compressor housing is formed by fixing, with multiple through bolts105, the front housing 102, a center gasket (not illustrated), thecylinder block 101, a cylinder gasket (not illustrated), the suctionvalve forming body (not illustrated), the valve plate 103 illustrated inFIG. 3, the discharge valve forming body 138 illustrated in FIG. 4, ahead gasket 139 illustrated in FIG. 6, and the cylinder head 104illustrated in FIG. 5.

In the cylinder head 104, a suction passage 104 a is formed tocommunicate between a low pressure side refrigerant circuit (suctionside refrigerant circuit) of a vehicle air conditioning system(refrigerant device) and the suction chamber 141. Accordingly, thesuction chamber 141 is connected to the low pressure side refrigerantcircuit of the refrigerant device. The suction passage 104 a is linearlyextended so as to cross a part of the discharge chamber 142 toward thesuction chamber 141 from the outside of the cylinder head 104.

The suction chamber 141 is partitioned into a first space 141 aconnected to the suction passage 104 a and a second space 141 bconnected to the suction hole 103 a by a partition member 150 integrallyformed with the head gasket 139. The first space 141 a and the secondspace 141 b are communicated by a communication hole 150 a (illustratedin FIG. 6) formed in the partition member 150 as a communicationpassage. The first space 141 a is configured to allow a low pressurerefrigerant gas to flow into the first space 141 a from a low pressureside refrigerant circuit via the suction passage 104 a, and the firstspace 141 a is configured to separate a lubricating oil mixed in therefrigerant gas and to store the separated lubricating oil at a lowerside thereof in a gravity direction (bottom portion of the space).Therefore, the first space 141 a corresponds to a storage area accordingto the present invention. The second space 141 b is configured tointroduce a refrigerant gas, which has flowed into the second space 141b through the communication hole 150 a from the first space 141 a andseparated from a lubricating oil, to the suction hole 103 a. Therefore,the second space 141 b corresponds to an inflow area according to thepresent invention. The partition member 150 will be described in detailbelow.

A muffler 160 for reducing noise and vibration caused by refrigerantpulsation is provided on the cylinder block 101 at an upper portionthereof. The muffler 160 is formed by fixing a lid member 106 with abolt via a sealing member (not illustrated) to a forming wall 101 bdivisionally formed at the upper portion of the cylinder block 101. Acheck valve 200 is arranged in a muffler space 143 in the muffler 160,to reduce a backward flow of a refrigerant gas from a discharge siderefrigerant circuit to the discharge chamber 142.

The check valve 200 is arranged at a connecting portion between acommunication passage 144 and the muffler space 143, the communicationpassage 144 extending across the cylinder head 104, the valve plate 103,and the cylinder block 101 and communicating with the discharge chamber142. The check valve 200 operates in response to a pressure differencebetween the communication passage 144 (upstream side) and the mufflerspace 143 (downstream side). When the pressure difference is less than apredetermined value, the check valve 200 blocks the communicationpassage 144. When the pressure difference is greater than thepredetermined value, the check valve 200 opens the communication passage144. Therefore, the discharge chamber 142 is connected to a dischargeside refrigerant circuit of a vehicle air conditioning system via adischarge passage including the communication passage 144, the checkvalve 200, the muffler space 143, and a discharge port 106 a.

In the cylinder head 104, a control valve 300 is provided.

The control valve 300 is provided in a pressure supply passage 145provided as a first passage that communicates between the dischargechamber 142 and the crank chamber 140 on a back side of the piston 136.The control valve 300 adjusts an opening of the pressure supply passage145 and controls an amount of the discharge refrigerant gas to beintroduced to the crank chamber 140. Also, a refrigerant in the crankchamber 140 flows to the second space 141 b of the suction chamber 141via a pressure releasing passage 146 provided as a second passage thatpasses through the communication passage 101 c, a space 101 d, anorifice 103 c formed in the valve plate 103 illustrated in FIG. 3, and acommunication hole 138 b formed in the discharge valve forming body 138illustrated in FIG. 4. Thus, the control valve 300 changes the pressurein the crank chamber 140, which in turn changes the inclination of theswash plate 111, that is, a stroke of the piston 136. As a result, adischarge displacement of the variable-displacement compressor 100 canbe varied. Although the orifice 103 c is a fixed orifice in theembodiment, the orifice 103 c may be a variable orifice.

The control valve 300 according to the embodiment is a control valvethat operates in response to an external electrical signal. FIG. 2illustrates a configuration thereof.

The control valve 300 includes: a first pressure-sensitive chamber 302that is formed in a valve housing 301 and communicates with the crankchamber 140 by the pressure supply passage 145 on the crank chamber 140side via a communication hole 301 a; a valve chamber 303 thatcommunicates with the discharge chamber 142 by the pressure supplypassage 145 on the discharge chamber 142 side via a communication hole301 b; a valve hole 301 c that is open at one end thereof to the firstpressure-sensitive chamber 302 and is open at the other end thereof tothe valve chamber 303; a valve body 304, one end of which is arranged inthe valve chamber 303 and opens and closes the valve hole 301 c, thevalve body 304 being slidably supported by a support hole 301 d formedin the valve housing 301; a bellows assembly 305 that is provided with aspring in an evacuated inside thereof, and is arranged in the firstpressure-sensitive chamber 302, the bellows assembly 305 receiving apressure in the crank chamber 140; a connecting portion 306 that isattachably and detachably connected to the bellows assembly 305 at oneend thereof and is fixed to one end of the valve body 304 at the otherend thereof; a second pressure-sensitive chamber 307 that is blockedfrom the valve chamber 303, and in which the other end of the valve body304 is arranged, the second pressure-sensitive chamber 307 communicatingwith the second space 141 b of the suction chamber 141 by a pressureintroducing passage 147, to be described later, via a communication hole301 e; a solenoid rod 304 a that is integrally formed with the valvebody 304, and in which a movable core 308 is press-fitted at an endportion of the solenoid rod 304 a opposite to the valve body 304; afixed core 309 that is arranged at an outer periphery of the solenoidrod 304 a and is arranged to face the movable core 308, being spacedwith a predetermined gap; a spring 310 that is interposed between thefixed core 309 and the movable core 308, and elastically biases thevalve body 304 in a valve opening direction via the movable core 308 andthe solenoid rod 304 a; a cylindrical member 312 that is arranged at anouter periphery of the fixed core 309 and fixed to a solenoid housing311, and that is made of a nonmagnetic material; and an electromagneticcoil 313 that is accommodated in the solenoid housing 311 so as tosurround the cylindrical member 312. Also, three O rings 313 a to 313 care arranged at an outer periphery of the control valve 300. By the Orings 313 a to 313 c, a receiving space of the control valve 300 formedin the cylinder head 104 is partitioned into an area in which a pressurein the crank chamber 140 is applied, an area in which a pressure in thedischarge chamber 142 is applied, and an area in which a pressure in thesuction chamber 141 is applied.

In the control valve 300 having such a configuration, if a bellowseffective area Sb of the bellows assembly 305, a pressure receiving areaSv for receiving a pressure in the crank chamber 140 applied to thevalve body 304 from the valve hole 301 c side, a pressure receiving areaSr for receiving a pressure in the suction chamber 141 (second space 141b) applied to the valve body 304 in the second pressure-sensitivechamber 307 are set to approximately the same value, a force acting onthe valve body 304 is represented by the following formula (1):

Ps=−(1/Sb)·F(i)+(F+f)/Sb   (1)

where, Ps denotes a pressure in the suction chamber 141 (second space141 b), F(i) denotes an electromagnetic force, f denotes a biasing forceof the spring 310, and F denotes a biasing force of the bellows assembly305.

Therefore, the control valve 300 adjusts an opening of the pressuresupply passage 145 communicating between the discharge chamber 142 andthe crank chamber 140 so that a pressure Ps in the suction chamber 141(second space 141 b), which has been introduced via the pressureintroducing passage 147, is maintained to a predetermined valuedetermined based on a current flowing to an electromagnetic coil 313 inresponse to an external signal, to thereby control an amount of adischarge refrigerant gas to be introduced to the crank chamber 140, tocontrol a discharge displacement of the variable-displacement compressor100. The pressure Ps in the suction chamber 141 (second space 141 b) canbe varied from the outside by adjusting a current flowing to theelectromagnetic coil 313.

While an air conditioner is operating, i.e., in a state in which thevariable-displacement compressor 100 is operating, an energizationamount of the electromagnetic coil 313 is adjusted based on an externalsignal, a discharge displacement is variably controlled so that apressure in the suction chamber 141 (second space 141 b) becomes apredetermined value and a pressure in the suction chamber 141 isappropriately controlled in response to the external environment.Although the control valve 300 in the embodiment operates in response toan external signal, a mechanical control valve that operates by sensinga pressure in a suction chamber may be used.

Next, the above-described partition member 150 and the pressureintroducing passage 147 will be described in detail with reference toFIGS. 3 to 9.

The partition member 150 is integrally formed by making a center of thehead gasket 139 illustrated in FIG. 6, i.e., a portion facing thesuction chamber 141 at a center of the cylinder head 104, protrudetoward the suction chamber 141 by stamping. By the partition member 150,the suction chamber 141 is partitioned into the first space 141 a towhich the suction passage 104 a is connected, and the second space 141 bto which the suction hole 103 a is connected. In the head gasket 139, aretainer 139 a for restricting an opening of the discharge valve 138 ais formed in an area corresponding to the discharge chamber 142. Thehead gasket 139 is a rubber-coated metal thin plate. Therefore, thepartition member 150 integrally formed with the head gasket 139 is alsorubber-coated.

The second space 141 b partitioned by the partition member 150 includes,as illustrated in FIG. 7, a central space 141 b 1 and guide passages 141b 2 radially extended toward the suction holes 103 a from the centralspace 141 b 1. The guide passage 141 b 2 includes a bottom wall 150 band side walls 150 c as illustrated in FIG. 8. As illustrated in FIG. 7,the guide passage 141 b 2 includes an area in which the bottom wall 150b is inclined so that a passage sectional area is reduced toward each ofthe suction holes 103 a, which are formed in the valve plate 103 to beannularly arranged at approximately equal intervals around an axis O ofthe drive shaft 110 at an approximately equal distance from the axis Oof the drive shaft 110.

Furthermore, in the partition member 150, two communication holes 150 athat communicate between the first space 141 a and the second space 141b are formed to be open to two guide passages 141 b 2 as illustrated inFIG. 6. The communication hole 150 a is formed by adjusting the positionthereof so that a predetermined amount of a lubricating oil can bestored in the first space 141 a. Specifically, the communication hole150 a is open to a position that is above the axis O of the drive shaft110 in a gravity direction and outside an area on an extension of thesuction passage 104 a into the suction chamber 141, in order to preventa main flow of a suction refrigerant, which has flowed into the firstspace 141 a from the suction passage 104 a, from directly flowing intothe communication hole 150 a. Also, an orifice 150 d that communicatesbetween the first space 141 a and the second space 141 b is formed inthe bottom wall 150 b of the guide passage 141 b 2 positioned below theaxis O of the drive shaft 110 in a gravity direction. An upper side inFIGS. 3 to 6 is an upper side in a gravity direction.

Since the communication hole 150 a is located above the axis O of thedrive shaft 110 in a gravity direction, the first space 141 a acts as anoil storage chamber for storing a lubricating oil returned from an airconditioning system with an inflow refrigerant gas. An opening area ofthe orifice 150 d is set so that an appropriate amount of a lubricatingoil is stored in the first space 141 a. The orifice 150 d acts as an oilreturn passage, which gradually returns a lubricating oil stored in thefirst space 141 a to the second space 141 b. Therefore, the first space141 a acts as a part of the suction passage, the communication hole 150a substantially acts as an exit of the suction passage, and the secondspace 141 b substantially acts as a suction chamber.

Although the communication holes 150 a and the orifice 150 d (oil returnpassage) are formed in the partition member 150, these may be formed inthe cylinder head 104. Also, the number of the communication holes 150 ais not limited to two, and it may be any number as long as it is one ormore. Furthermore, although a position of the communication hole 150 ais not limited to a position above the axis of the drive shaft 110 in agravity direction, the communication hole 150 a may be positioned at anyposition as long as it is arranged above the orifice 150 d, and theposition may be preferably adjusted depending on a target storage amountof lubricating oil in the first space 141 a.

Multiple pressing protrusions 104 d protruding toward the valve plate103 are formed on a surface of a suction chamber forming wall of thecylinder head 104 facing the valve plate 103, i.e., on a bottom wall 104c of the suction chamber 141, and are arranged in a substantiallyannular manner. The pressing protrusions 104 d press, toward the valveplate 103, a flat portion 139 b of the head gasket 139 formed betweenthe guide passages 141 b 2 at a periphery of the partition member 150,and accordingly press the valve plate 103 via the head gasket 139 andthe discharge valve forming body 138. In this manner, the partitionmember 150 can be reliably retained on the valve plate 103 side. Herein,the pressing protrusions 104 d correspond to a protruded portionaccording to the present invention.

The pressure introducing passage 147 includes: a communication hole 138c formed in the discharge valve forming body 138; a long hole 103 dformed in the valve plate 103; a communication hole 138 d formed in thedischarge valve forming body 138; a communication hole 139 d formed inthe head gasket 139; a communication hole 104 e formed in the pressingprotrusion 104 d formed in the cylinder head 104 as illustrated in FIG.9; and a space 104 f partitioned by two O rings 313 a and 313 b in thereceiving space of the control valve 300 in the cylinder head 104, andconnected to the communication hole 301 e of the control valve 300, asillustrated in FIG. 9. The long hole 103 d is closed by a suction valveforming body (not illustrated) arranged between the cylinder block 101and the valve plate 103.

Therefore, a pressure in the second space 141 b of the suction chamber141 is introduced to the second pressure-sensitive chamber 307 of thecontrol valve 300 via this pressure introducing passage 147 and thecommunication hole 301 e. An open end of the pressure introducingpassage 147 on the second space 141 b side is the communication hole 138c. The communication hole 138 c is arranged above, in a gravitydirection, the orifice 150 d formed in the partition member 150.

In the variable-displacement compressor having such a configuration,according to the present embodiment, from an inflow refrigerant gascontaining a lubricating oil, which has flowed into the first space 141a from the suction passage 104 a, the lubricating oil is separated inthe first space 141 a. The separated lubricating oil is stored in thebottom portion (lower side in a gravity direction) of the first space141 a. The remaining refrigerant gas, from which the lubricating oil hasbeen separated, flows into the second space 141 b via the communicationhole 150 a, and flows toward each suction hole 103 a along the guidepassages 141 b 2, and then is drawn into the cylinder bore 101 a fromeach suction hole 103 a by the reciprocation of the piston 136.

In this manner, since what flows into the second space 141 b of thesuction chamber 141 is the remaining refrigerant gas, from which thelubricating oil has been separated, an amount of the lubricating oilflowing into the second pressure-sensitive chamber 307 of the controlvalve 300, to which a pressure in the second space 141 b is introducedvia the pressure introducing passage 147, can be reduced.

Therefore, the inside of the control valve 300, especially the secondpressure-sensitive chamber 307 and the inside of the cylindrical member312 communicating with the second pressure-sensitive chamber 307, arenot filled with the lubricating oil, and sensitivity of the controlvalve 300 is not reduced by operation failure caused by inflow of thelubricating oil.

Also, since the communication hole 138 c, which is an open end of thepressure introducing passage 147 on the second space 141 b side, isarranged above, in a gravity direction, the orifice 150 d formed in thepartition member 150, when the lubricating oil stored in the first space141 a is returned to the second space 141 b via the orifice 150 d, thelubricating oil does not flow into the pressure introducing passage 147,and control operation of the control valve 300 is not interrupted. Thelubricating oil gradually flowing into the second space 141 b from thefirst space 141 a by the orifice 150 d contributes to lubricate eachcomponent of the variable-displacement compressor 100.

The lubricating oil separated from the refrigerant gas is drawn into thecylinder bore 101 a, and therefore an oil flowing out from thevariable-displacement compressor 100 toward an air conditioning systemis reduced. Accordingly it contributes to reduce an oil circulationrate.

Furthermore, since each suction hole 103 a is partitioned by the guidepassages 141 b 2 radially formed from the central space 141 b 1, therefrigerant gas smoothly flows toward each suction hole 103 a, and thus,mutual interference of a refrigerant gas toward each suction hole 103 ais prevented. Accordingly it contributes to reduce a pulsation level ofa suction pressure.

In the present embodiment, since the partition member 150 is integrallyformed with the head gasket 139 by stamping the head gasket 139, anadditional new component as a partition member is not needed, and astructure for fixing the partition member 150 in the suction chamber 141is not needed. As a result, a cost increase by employing the partitionmember 150 can be suppressed.

In the present embodiment, the partition member 150 is integrally formedwith the head gasket 139. However, the partition member 150 may beformed to be a member separated from the head gasket 139.

Furthermore, in the present embodiment, the lubricating oil stored inthe first space 141 a is returned to the second space 141 b by theorifice 150 d. However, the first space 141 a and the crank chamber 140may be communicated by an oil return passage. In this manner, even whenthe variable-displacement compressor 100 stops rotating, oil stored inthe first space 141 a can be returned to the crank chamber 140.

Although the communication hole 150 a is provided in the embodiment as acommunication passage for introducing the refrigerant gas, from whichthe oil has been separated, to the second space 141 b, a cylindricalcommunication passage protruding to the first space 141 a may beprovided instead of the hole. This may improve an oil separation effectin the first space 141 a.

Although an example of a clutch-less compressor as thevariable-displacement compressor 100 is illustrated in the embodiment,an electromagnetic clutch may be mounted on a variable-displacementcompressor. The present invention is not limited to a swash plate type,and it is applicable to a swing-plate type variable-displacementcompressor.

REFERENCE SYMBOL LIST

100 Variable-displacement compressor

103 a Suction hole

103 c Orifice

104 a Suction passage

136 Piston

140 Crank chamber

141 Suction chamber

141 a First space

141 b Second space

142 Discharge chamber

145 Pressure supply passage (first passage)

146 Pressure releasing passage (second passage)

147 Pressure introducing passage

150 Partition member

150 a Communication hole

300 Control valve

1. A variable-displacement compressor comprising: a piston thatcompresses a refrigerant gas drawn from a suction chamber via a suctionhole and discharges the refrigerant gas to a discharge chamber via adischarge hole; a first passage that communicates between a crankchamber on a back side of the piston and the discharge chamber; acontrol valve provided in the first passage and that controls an openingof the first passage; a second passage that communicates between thecrank chamber and the suction chamber, and that is provided with anorifice; and a pressure introducing passage configured to introduce apressure in the suction chamber to the control valve, wherein thecontrol valve controls an opening of the first passage depending on thepressure in the suction chamber, which has been introduced from thepressure introducing passage, so as to control a pressure in the crankchamber, so that a stroke of the piston is changed, and accordingly, adischarge displacement of a refrigerant gas is varied, wherein thesuction chamber includes a storage area for separating a lubricating oilfrom a refrigerant gas inflowing from a suction passage and for storingthe lubricating oil, and an inflow area into which the refrigerant gas,from which the lubricating oil has been separated, flows, wherein thesecond passage is open to the inflow area, and wherein the pressureintroducing passage is open to an inflow area into which the refrigerantgas, from which the lubricating oil has been separated, flows, so as tointroduce the pressure in the suction chamber to the control valve. 2.The variable-displacement compressor according to claim 1, wherein thesuction chamber is partitioned, by a partition member, into a firstspace to which the suction passage is open, and that acts as the storagearea, and a second space to which the suction hole and the pressureintroducing passage are open, and that acts as the inflow area, whereina communication passage that communicates between the first space andthe second space is provided.
 3. The variable-displacement compressoraccording to claim 2, wherein the communication passage is formed in thepartition member by adjusting a position thereof, so as to be capable ofstoring a predetermined amount of the lubricating oil in the firstspace.
 4. The variable-displacement compressor according to claim 2,wherein the partition member is formed by protruding, into a suctionchamber, a portion of a head gasket facing a suction chamber, the headgasket being interposed between a valve plate, in which the suction holeand the discharge hole are formed, and a cylinder head, in which thesuction chamber and the discharge chamber are formed.
 5. Thevariable-displacement compressor according to claim 4, wherein, on asurface of a suction chamber forming wall of the cylinder head facingthe valve plate, a protruded portion for pressing a periphery of thepartition member of the head gasket onto the valve plate, is formed toprotrude.